Why are videos too black on TV/HDTV screens with the new nvidia drivers?
Since nVidia drivers 191.07 were released, many are experiencing too dark videos on TV/HDTV screens.
With 191.07, when "With the video player settings" is selected in the nvidia driver (Video->"Adjust video color settings"), it is forcing PC level settings.
On 191.03 and previous drivers, "With the video player settings" did what it should.
To solve this, go to nvidia's Video->"Adjust video color settings", select "With the NVIDIA settings", go on the "Advanced" tab, and set "Dynamic Range" to: Limited (16-235).
For more detailed discussion on this issue, go to here